引用先前的节点(Referencing previous nodes)#

在 n8n 中处理数据时，你经常需要引用当前节点或工作流中先前节点的信息。

🌐 When working with data in n8n, you'll often need to reference information from the current node or from previous nodes in your workflow.

常见的引用方式(Common ways of referencing)#

访问数据的最常用方法是：

🌐 The most frequently used methods for accessing data are:

这些方法在表达式和代码节点中都适用：

🌐 These methods work in both expressions and the Code node:

用于处理当前节点输入的方法。某些方法和变量在代码节点中不可用。

🌐 Methods for working with the input of the current node. Some methods and variables aren't available in the Code node.

Python support

You can use Python in the Code node. It isn't available in expressions.

JavaScriptPython

Method	Description	Available in Code node?
`$binary`	Shorthand for `$input.item.binary`. Incoming binary data from a node
`$input.item`	The input item of the current node that's being processed. Refer to Item linking for more information on paired items and item linking.
`$input.all()`	All input items in current node.
`$input.first()`	First input item in current node.
`$input.last()`	Last input item in current node.
`$input.params`	Object containing the query settings of the previous node. This includes data such as the operation it ran, result limits, and so on.
`$json`	Shorthand for `$input.item.json`. Incoming JSON data from a node. Refer to Data structure for information on item structure.	(when running once for each item)
`$input.context.noItemsLeft`	Boolean. Only available when working with the Loop Over Items node. Provides information about what's happening in the node. Use this to determine whether the node is still processing items.

Method	Description
`_input.item`	The input item of the current node that's being processed. Refer to Item linking for more information on paired items and item linking.
`_input.all()`	All input items in current node.
`_input.first()`	First input item in current node.
`_input.last()`	Last input item in current node.
`_input.params`	Object containing the query settings of the previous node. This includes data such as the operation it ran, result limits, and so on.
`_json`	Shorthand for `_input.item.json`. Incoming JSON data from a node. Refer to Data structure for information on item structure. Available when you set Mode to Run Once for Each Item.
`_input.context.noItemsLeft`	Boolean. Only available when working with the Loop Over Items node. Provides information about what's happening in the node. Use this to determine whether the node is still processing items.

用于处理其他节点输出的方法。有些方法和变量在代码节点中不可用。

🌐 Methods for working with the output of other nodes. Some methods and variables aren't available in the Code node.

JavaScript

Method	Description	Available in Code node?
`$("<node-name>").all(branchIndex?, runIndex?)`	Returns all items from a given node. If `branchIndex` isn't given it will default to the output that connects `node-name` with the node where you use the expression or code.
`$("<node-name>").first(branchIndex?, runIndex?)`	The first item output by the given node. If `branchIndex` isn't given it will default to the output that connects `node-name` with the node where you use the expression or code.
`$("<node-name>").last(branchIndex?, runIndex?)`	The last item output by the given node. If `branchIndex` isn't given it will default to the output that connects `node-name` with the node where you use the expression or code.
`$("<node-name>").item`	The linked item. This is the item in the specified node used to produce the current item. Refer to Item linking for more information on item linking.
`$("<node-name>").params`	Object containing the query settings of the given node. This includes data such as the operation it ran, result limits, and so on.
`$("<node-name>").context`	Boolean. Only available when working with the Loop Over Items node. Provides information about what's happening in the node. Use this to determine whether the node is still processing items.
`$("<node-name>").itemMatching(currentNodeInputIndex)`	Use instead of `$("<node-name>").item` in the Code node if you need to trace back from an input item.